Interfering With Lipid Raft Association: A Mechanism to Control Influenza Virus Infection By Sambucus Nigra

Sambucus nigra (elder) are broadly used species to treat microbial infections. Thepotential antiviral activity and mechanism action of elder fruit (EF) in human epithelium cell(A549) cultures infected with H9N2 influenza virus were determined. The effect of variousconcentrations of EF on influenza virus replication was examined by using virus titration,quantitative real time RT-PCR, fusion and lipid raft assays following two treatment procedures:A) pre-treated H9N2 virus with each concentration of EF extract and transfection of A549 cellcultures, and B) each concentrations of EF was added to H9N2 virus infected-cell culturesfollowing virus adsorption. In both treatments with lower doses of EF increased viral titer aswell as synthesized viral nucleoprotein as indicating the herb had no inhibitory effects on virusreplication. In (B) trial with higher doses, 40 and 80 μg/mL of EF, a significant decrease invirus titer and viral protein synthesis were shown in EF treated cells indicating the herb affecteither entry of viruses or inhibition virus particle release. The results suggest that EF treatmentof the influenza virus infected-human epithelial cells may involve in lipid raft associationwhich function as platform for formation of viral membrane fusion and budding. Differencesintreatment time and dose of EF extract in infected cells with influenza virus have a marked effecton the efficacy of the herb.